This invention relates to machines for making tubular containers from flat blanks of sheet material. In another aspect this invention relates to machines easily adaptable for making more than one size of tubular containers from appropriately sized flat blanks of sheet material. In yet another aspect this invention relates to means which allow one to quickly modify the circumferential dimension or shape of the container that can be formed by a machine that forms tubular containers from flat blanks of sheet material. Further the invention relates to mandrel means employed as the forming surface in producing tubular containers from flat blanks or sheet material.
Tubular containers are often made from flat blanks by wrapping a blank around a mandrel and sealing the overlapping margins of the blank to form a tubular container side wall. Examples of machines employing mandrels in the formation of tubular containers are provided by A. A. Barnes et al, U.S. Pat. No. 2,726,583, issued Dec. 13, 1955; Paul J. Corazzo, U.S. Pat. No. 3,289,552, issued Dec. 6, 1966; and Silvio T. Farfaglia et al, U.S. Pat. No. 3,890,765, issued June 24, 1975. In using these types of machines, when one desires to produce tubular containers of a different circumferential dimension or shape it has generally been necessary to remove the existing mandrel from its mounting on the machine and to substitute another mandrel which will produce a container having the desired circumferential size or shape. In machines such as illustrated in the above-mentioned patents, the removal of mandrels can be extremely time consuming. Also the replacement of mandrels of one size or shape with those of another size or shape generally necessitates many other adjustments in the overall container forming machine. Thus improvements which will minimize the complexity of adjustments required when such machines are modified to produce containers of a different size or shape will be of significant advantage in this field.
Accordingly, an object of this invention is to provide means whereby one can switch from making containers of one circumferential shape or size to making containers of another circumferential shape or size with less complex adjustments and alterations than required heretofore.
Also it is an object of this invention to provide an assembly which serves as mandrel for forming tubular container of one size and which is easily disassembled to produce a means which can serve as a mandrel for forming tubular container of a smaller size.
Another object of the present invention is to provide an apparatus easily modified for forming tubular containers of various circumferential dimensions or shapes.
Other aspects, objects, and advantages of the present invention will become apparent from a study of the disclosure, the appended claims, and the provided drawings.
In accordance with the present invention a means is provided for quickly modifying the circumferential dimension or shape of the container that can be formed by an apparatus which forms a tubular container by first clamping a flat blank of sheet material against a basic mandrel with a clamping means comprising a basic clamping shoe and a clamping arm capable of moving the clamping shoe from a position which will allow a blank to be placed between the basic clamping shoe and the basic mandrel to a position which can hold a portion of the blank against the basic mandrel and then folding the clamped flat blank around the basic mandrel, wherein the basic mandrel is designed so that the formed tubular container can be slid off said mandrel. The means is a kit comprising (1) at least one tubular mandrel sleeve being designed so that if a tubular container were formed by folding an appropriately sized blank around the mandrel sleeve the thus formed tubular container could be slid off the mandrel sleeve and so that the mandrel sleeve is capable of being removably secured around said basic mandrel in coaxial alignment therewith and (2) a corresponding replacement clamping shoe for each tubular mandrel sleeve, each replacement clamping shoe being of such size that when the corresponding mandrel sleeve is secured around the basic mandrel and the replacement clamping shoe is substituted for the basic clamping shoe, the thus altered clamping means without further modification or adjustment will be able to function to move the replacement clamping shoe from a position which allows a blank to be placed between said replacement clamping shoe and the corresponding mandrel sleeve to a position in which the replacement clamping shoe will hold a blank against the corresponding mandrel sleeve.
Any suitable means can be employed for removably securing the mandrel sleeve around the basic mandrel and assuring coaxial alignment with said basic mandrel. One preferred means involves removably securing to an end of the basic mandrel an end plate which will secure the mandrel sleeve around the basic mandrel by clamping the mandrel sleeve between said end plate and a basic mandrel mounting flange. Other examples of suitable attaching means include at least one countersunk fastening means such as a bolt in the mandrel sleeve that can be attached to a respective threaded portion in the basic mandrel, threaded portions on the interior of one end of the mandrel sleeve which can interlock with corresponding threaded portions on a portion of the basic mandrel mounting sleeve, cooperating lug-and-slot type locking devices on the interior of end of the mandrel sleeve and a portion of the basic mandrel mounting flange, which lug-and-slot devices enable the mandrel sleeve to be slid over the portion of the flange and then twisted to secure the mandrel from thereafter sliding along the length of the basic mandrel.
Preferably the internal diameter of the tubular mandrel sleeve is larger than that necessary for allowing the mandrel sleeve to be removably secured around the basic mandrel. By employing such a mandrel sleeve there is less likelihood for sticking which would inhibit the attachment or subsequent removal of the mandrel sleeve. When such a mandrel sleeve is employed with a basic mandrel connected to a mandrel mounting flange, the coaxial alignment can be provided by suitably arranged indentation means and corresponding projection means on the flange and on the end of the mandrel sleeve that will fit over a portion of the mounting flange when the mandrel sleeve is secured around said basic mandrel. The terms indentation means and projection means are intended to include one or a plurality of suitable indentations as well as suitable continuous cooperating indentation and projection.
When the mandrel sleeve is secured by being clamped between the flange and a removably secured end plate, further assurance that the coaxial alignment will be maintained during the production of tubular containers can be provided by suitable cooperating projection means and indentation means on the end plate and the end of the mandrel sleeve when the two contact.
Also according to the present invention there is provided an apparatus which can be easily altered to produce a container having a different circumferential dimension or shape. The apparatus includes a basic mandrel having first and second ends. The second end of the basic mandrel is attached to a supporting means. The basic mandrel is shaped so that if a flat blank were wrapped around it to form a tube, the thus formed tube could be slid off the first end of the basic mandrel. Surrounding the basic mandrel and in coaxial alignment therewith is a removably secured tubular mandrel sleeve having first and second ends adjacent the respective first and second ends of the basic mandrel. The tubular sleeve is also designed so that if a flat blank were wrapped around it to form a tube, the thus formed tube could be slid off the first end of the mandrel sleeve. Associated with the mandrel sleeve is a clamping means which will allow a flat blank to be placed between itself and the mandrel sleeve and then serve to hold a portion of the flat blank in firm contact with the mandrel sleeve while the flat blank is being folded. The clamping means is adapted so that, if the apparatus were modified by employing a larger mandrel sleeve or by removing the mandrel sleeve to expose the basic mandrel, the clamping means could be adjusted or altered so that it could respectively function to allow a blank to be placed between itself and larger mandrel sleeve and then to hold the flat blank in firm contact with the larger mandrel sleeve while the flat blank was being folded or to allow a blank to be placed between itself and the basic mandrel and then to hold the flat blank in firm contact with the basic mandrel while the flat blank was being folded. Also included in the apparatus is a folding means designed to fold a blank around the mandrel sleeve after the blank has been clamped against the mandrel sleeve and being also adapted or capable of being adjusted to fold a blank at least either around the basic mandrel of the mandrel sleeve if the apparatus were modified by removing the mandrel sleeve or around a larger mandrel sleeve if the apparatus were modified by employing a larger mandrel sleeve.